Percutaneous biopsy of the breast is a well-accepted alternative to open surgical biopsy with needle localization for those lesions seen by mammography or ultrasound but not able to be felt by the surgeon. When percutaneous biopsy is performed, it is frequently necessary to place a metal clip at the site of biopsy. This is done for several reasons. For example, the lesion biopsied might be partially or entirely removed. If the lesion is proven to be malignant, it is necessary to subsequently do a wide excisional biopsy after needle localization to remove any residual malignancy. The clip makes the site of biopsy apparent, assuring accurate localization. In addition, if something is seen on both mammography and ultrasound, it is not always certain that the lesions are one and the same. A biopsy under ultrasound guidance with placement of a clip allows confirmation by mammography that the lesion is the same or different than the one seen on the mammogram. Further, the presence of a clip seen on a mammogram alerts the radiologist that a biopsy has been performed, prompting the radiologist to more closely evaluate the site of biopsy.
The vast majority of percutaneous breast biopsies are performed under art-disclosed stereotactic guidance techniques, and generally use a device known as the Mammotome® (by Johnson & Johnson). The clip that is employed is generally prone to pinching a minute amount of breast tissue. Sometimes, the clip may fail to hold onto the tissue or the clip may migrate to a different undesired location.
U.S. Surgical has produced a clip from a wire with a memory that is delivered into the breast and forms a ring. It is larger in diameter than the Mammotome® device clip and can grab significantly more tissue. The clip is an alloy containing nickel. Recent indications are that U.S. Surgical may no longer manufacture this clip, thus creating a potential supply issue for existing users.
SenoRx, Inc. produces metal markers embedded in Gelfoam pellets (a product that promotes clotting of blood), called Gel Mark™. The product is packaged to include a plurality of pellets and one radiographic marker. The pellets, however, potentially result in undesired migration of particles.
Although there is current production of a hand-held Mammotome® device, for the purpose of ultrasound guided biopsy, for some users this device may be awkward and cumbersome to use. The majority of ultrasound-guided biopsies are done with use of Tru-cut needles. This can be done through a coaxial needle. A Bard 12 gauge biopsy needle could be used through an 11 gauge coaxial needle. Through this 11 gauge coaxial needle, a U.S. Surgical clip might also be delivered, although U.S. Surgical is not believed to have marketed their clip for use during ultrasound-guided biopsies.
Another product is manufactured by Inrad. This clip is used for placement during ultrasound-guided biopsy because the delivery device is steel and does not provide the flexibility necessary for delivery through the Mammotome® needle. This delivery device has a beveled tip, allowing advancement through breast tissue without a coaxial needle.
Breast biopsies using an 11 gauge coaxial needle have been performed. However, most biopsies are typically done using smaller needles, e.g. a 14 gauge biopsy needle with 13.5 gauge coaxial needle. Such small sizes, in many environments, however, are believed to be too small to efficiently allow advancement of the delivery device of current commercially available clips.
Turning to another consideration, when a cyst in the breast is aspirated, a spectrum of different types of fluid can be recovered. These might range in color from white to yellow to green or brown. They may be mucousy or bloody and thus can be thick or thin. Some physicians send all samples for cytology analysis, while other physicians may send only grossly suspicious samples (e.g. mucousy or bloody). Regardless of which cyst fluids are sent for cytology, once a cyst is evacuated or in the event that a cyst cannot be fully evacuated because it contains a solid component, a radiologist would like to place a clip into the lesion. It is often important to mark the cyst so that should the cytology prove malignant, or otherwise require further attention, the exact site of the lesion would be known and a needle localization could be subsequently performed.
In one particular aspect, with reference to FIGS. 1a and 1b, common prior biopsy instruments generally employ a clip delivery device 1 with a side tube opening 2 having a center “C” disposed within a needle 3. Typically the devices are constructed so that the user needs to longitudinally re-position the instrument (e.g., on the order of about 5 mm to 12 mm or more) between steps of removal of tissue, aspiration of a cyst, or both and marking of a biopsy site “A” with a clip 4, in order to locate the clip precisely in the biopsy site. This is because the distance “d” from the forward end of a leading portion 5 of the clip delivery device is less than the distance “D” to a center portion “CA” of a biopsy site. For example, FIG. 1a illustrates an instrument with clip delivery device having a side tube opening for providing a side hole clip delivery function, but showing the result if there is no longitudinal re-positioning of the clip delivery device or the needle. As seen, upon deployment, the clip is not located precisely at the “CA” biopsy site “A”. As seen for example in FIG. 1b, in order to achieve precise location of the clip at the biopsy site “A”, it is necessary either to shift the entire needle longitudinally, or to retract the clip delivery device longitudinally, the former being shown in the drawing. Either way, another manual step is required of the user. It is desirous to avoid this need for longitudinal re-positioning, while still achieving precise placement of a clip at the biopsy site.
There is a need for improved devices for breast biopsy, cyst aspiration or both, to overcome the above-discussed disadvantages of current commercial products.
The following United States patents are also useful to more fully understand the context and application of the present invention and are all hereby expressly incorporated by reference herein: U.S. Pat. No. 6,161,034; U.S. Pat. No. 5,526,822; and U.S. Pat. No. 5,649,547. Devices disclosed in the above patents may be modified as desired to incorporate the inventive features disclosed herein.